Impact of Climate Change on Hinarchi Glacier and Bagrot River Runoff in Central Karakoram National Park of Gilgit-Baltistan, Pakistan

Abstract

<align:justify"> The effect of global warming and climate change on cryosphere in the mountainous region is quite evident as exhibited by reduction of snow cover and glacial receding. Regression analysis of Climate Research Unit (CRU) gridded data showed rising trend in average annual maximum temperature for the period 1901 to 2012.The annual mean minimum temperature for the same period indicated distinct rising rate 0.017 ˚C per year. The Annual mean temperature for the same period also increased at a rate of 0.013˚C per year. Similarly, Trend analysis performed on annual maximum temperature on Automatic Weather Station data set, where significant rising tendency observed i.e. 0.19˚C per year for the period 1993 to 2009 while the increasing trend of annual mean minimum temperature was not significant (0.06 ˚C) for the same period. Annual mean temperature for the same period is also rise at a rate of 0.13˚C per year. In order to smooth out short term variations and visualize the long term changes in temperature, five and ten year moving average of annual maximum, mean and minimum temperature were calculated. Generally, there is increasing trend in precipitation but the dry spells also prevailed in the whole region. Due to rising temperature, the ever fastest rate of glacial depletion is eventual on Hinarchi Glacier which retreated about 900m from its terminus during the last century. Bagrot river runoff trend was also determined based on hydrological data from the period 1966 to 2009 which shown decreasing trend.